Hearts will definitely be without midfielder Arnaud Djoum at Celtic Park this Sunday after Cameroon reached the African Cup of Nations quarter-finals.
The 27-year-old will remain on international duty in Gabon until Sunday at the earliest after Cameroon finished second in Group A to secure a quarter-final place. They are due to face Senegal on Saturday evening in Franceville.
Djoum will also miss next Wednesday's home match against Rangers if his country progress to the semi-finals. His role in the tournament so far has been peripheral, however, as he was an unused substitute in all three of Cameroon's group games.
He missed Sunday's Scottish Cup fourth round draw against Raith Rovers and will be absent for the replay on Wednesday.
His Tynecastle colleague Faycal Rherras is also at the African Cup of Nations with Morocco and could also miss the Celtic match. A draw against Ivory Coast in tomorrow's final Group C game could take the North Africans into the quarter-finals along with Cameroon.